I can't get the swr under 3

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I can't get the swr under 3


Post by MRooster »

Hello everybody, I just started a new job and they put me in a Freightliner M2 106 until my new Mack comes in. I brought my CB, Antenna and Coax with me from my old job and it worked fine (1.2-1.5 swr) on my KW T880. I'm running a old 5ft KW fiberglass antenna on a mirror mount and a cobra Stound tracker circa 99. Hooked everything up today and went to set the SWR with an older Asatic SWR meter. Sitting in the middle of the lot, no trees or power lines for 100ft in every direction it would not drop below 3.5. I'm at a loss here, any help would be appreciated
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Re: I can't get the swr under 3


Post by Bozo »


It sounds like you're experiencing a high SWR on your CB setup in the Freightliner M2 106. you can troubleshoot and improve your SWR:

1. Check the Antenna Installation:
- Ensure that the antenna is properly installed and securely mounted.
- Check for any damage to the antenna or coax cable that could affect performance.

2. Coaxial Cable:
- Inspect the coaxial cable for any cuts, kinks, or other damage.
- Make sure the connections are tight and free from corrosion.

3. Grounding:
- Verify that the antenna and coaxial cable are properly grounded to the vehicle's chassis.
- Ensure there is a good electrical connection between the antenna mount and the chassis.

4. Antenna Height and Placement:
- Check if the antenna is at an optimal height and position for your vehicle.
- Avoid mounting the antenna too close to other metal objects or antennas, which can cause interference.

5. SWR Meter Calibration:
- Calibrate your SWR meter according to the manufacturer's instructions before taking readings.
- Double-check that the SWR meter is functioning correctly.

6. Adjusting the Antenna Length:
- If possible, adjust the length of the antenna to try to achieve a lower SWR reading.
- Follow the antenna manufacturer's guidelines for adjusting the length based on SWR readings.

7. Testing in Different Locations:
- Try testing your SWR in different locations to see if there are any environmental factors affecting the readings.
- Avoid testing near large metal structures or buildings that could interfere with signals.


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Re: I can't get the swr under 3


Post by MDYoungblood »

Hello MRooster,

Welcome to the forum. First, don't get frustrated, it happens.
Start by checking a couple things, make sure the coax wasn't damaged in the removal from the other truck and that it isn't pinched on the new install.
Next check the meter and jumper, see if that could be the problem.
Being it is a old fiberglass antenna, check it for damage, especially at the threated end, the solder usually breaks away from the ferrule there.
Now check the mount and see if it is grounded (bonded) to the vehicle, a lot of new trucks are plastic.
Last thing, you could try leaning the antenna forward away from the windshield frame, sometimes that helps.
That is a few tips I can think of without actually seeing the install.


"321, West Manchester Township, PA"

Official Moderator - CBRT Complaint Department
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